# IC_LockdownRange

## C Specification

      #include <nitro/os.h>

      void IC_LockdownRange( void* startAddr, u32 nBytes );

## Description

This function locks and discards the contents of the instruction cache that is hit by the specified region; however, the usable area of cache decreases and the miss rate increases. `startAddr` is rounded down to the closest 32-byte boundary. `startAddr` + `nBytes` is rounded up to the closest 32-byte boundary.

## Internal Operation

This function operates registers 7 and 9 of the system control coprocessor.

## Arguments

`startAddr` | Lowest address in the region to be locked down
`nBytes` | Number of bytes of the region to be locked down

## Return Values

None.

## See Also

`IC_PrefetchRange
`

## Revision History

12/22/2003 Initial Version